Turbine blade mounting



Jan. 14, 1947. Q SQDERBERG 2,414,278

TURBINE BLADE MOUNTING I Filed July 23, 1943 2 Sheets-Sheet 1 INVENTOR FIG. I

m BE-RG 2,414,278

FIG-.2

FIG 3 INVENTOR are? Patented .Fan. i4, 19%? TURBINE BLADE IVEQEJN'EHNG Carl Kt. eoderberg, Weston, Mass. assignor to United Aircraft Corporation, East Hartford;

(Conn, a corporation of Delaware Application July 23, 1963, Serial No. 495,92d

-2 Ciaims. (Ci. 253--39) This invention relates to a blade mounting. stress discs extending perpendicular to the ams In mounting of turbine blades to resist the of the rotor. centrifugal forces resulting from high rotational The angle of convergence of the surfaces it speeds, various interconnections have been used and it on the discs is such that the intersection v between the blade root and the peripheries of the 5 of a line 32 at right angle to either surface and rotary disc to which the blades are attached. midway between opposite edges of those surfaces, These mountings, however, have been constructand a line to at right angle to surface 3i! or 32 ed generally without consideration of the weight and also midway between its edges, will be in a of the rotor. A feature of this invention is a plane 46 which is substantially midway between blade mounting which will hold the blade in place opposite side walls of one of the supporting discs in the rotor with a minimum of weight in both III or I2. In this way the load on the discs reblade root and rotor. sulting from the centrifugal force on the blade,

Blade mountings using a T-shape root section represented by arrow A, is entirely a radial load for the blade have been made in which the T- and is uniformly distributed across the entire shape root has parallel surfaces engaging with thickness of the discs. AtrowsB, C and D on cooperating cylindrical surfaces on the rotor. lines 42, 44 and 46 show the directions: of the Such an arrangement may cause parts of the loads on the disc from which it can be seen that root section of the blade and the cooperating there is no nding moment on the disc (excep parts of the rotor to be overstressed. With that t its extreme outer end)- in mind, another feature of this invention is a In the force diagram o 3. the dimensions blade mounting in which the load is substantially of the forces 011 the blade root and the (11505 are uniformly distributed, thereby making possible a shown, and o balancing of h se es So t at substantial reduction in the dimensions of the ad a forces n y re app to the discs 15 made parts. apparent.

Other objects and advantages will be apparent Ex pt for th ab e-d s ed p atin from the specification and laim a from t surfaces, the blade root is free from engagement accompanying drawings which illustrates an emwith the discs- The blade root is thus hold in bodiment of the inv ti contact with the discs by spaced cooperating ra- Fig. 1 is a sectional view through a section of dial Surfaces and Spaced cooperating converging the turbine rotor. surfaces arranged to apply a uniformly distrib- Fig. an a view on a. larger scale to show the uted load on t s e p ratin ylinblade mounting. drical surfaces hold the other cooperating sur- Fig. 3 is a force diagram. faces in engagement.

The rotor 8 has a pair of opposed discs in and It is to be understood that the invention is l2, supporting a row of turbine blad 14 t; their not limited to the specific embodiment herein ilperipheries. The rotor may have a, n b of lustrated and described, but may be used in other axially spaced rows of blades alternating with Ways Without depa t from its p l as defined rows of vanes on a turbine casing surrounding y the following s. the rotor. I claim:

Discs m and I2 have opposed converging sur- In a blade mounting in which a -shaped faces 16 and I8, Fig. 2, facing toward each other root is positioned between Opposed annular for engagement, with cooperating shoulders flanges on a support, the combination with forming converging surfaces 20 and 22 on root 24 spaced flanges on Said root having radial of blade l4. Surfaces l6 and i8 and also sur- 4, 93 i eiach tomer 5 g s z sai roo ac ng owar an con erg ng owar {3231 and 22 converge toward the up of the the tip of the blade, of cooperating radial surfaces on the supporting flanges facing away from each other and engaging withthe radial surfaces in the blade root, and cooperating shoulders on the flanges facing toward and diverging toward the axis of the flanges for'engagement with the Discs [0 and I2 also have peripheral flanges 26 and 28, the outer side surfaces of which are radial to cooperate with the inner radial surfaces 30 and 32 of inwardly extending flanges 34 and 36 on the blade root. The inner surfaces 38 and Shoulders on the r t, the angularity of the 40 on the flanges on the blade root may engage shoulders being such that the line of thrust on corresponding oy Surfaces on 8 5 In the diverging surface on each disc intersecting and 12. The discs are both essentially constantthe line of thrust on the radial surface at a point substantially in a radial plane centrally of the disc.

The combination with 'a blade root having opposed shoulders facing toward and converging toward the tip of the blade, and substantially radial surfaces facing each other and located between said shoulders and the blade tip, of a blade mounting including spaced discs forming a part of a rotor, the inner surfaces of said discs hav= ins opposed shoulders facing toward the ants of no the rotor and diverging toward the axis to engage with the shoulders on the blade root, said discs also having substantially radial surfaces facing awayqfrom each other and engaging the substantially radial surfaces on the blade root, the angularity of the shoulders being such that the line of thrust on each shoulder intersects the line of thrust on each radial surface at a point substantially in a radial plane centrally of the disc.

CARL R. SODERBERG. 

